This fitness tracker syncs to iOS,Android smart phones and pad.Requires iOS 7.1 and above or Android 4.4 and above.It Does NOT Work With Windows Phones. Devices using Bluetooth 4.0 wireless technology.Syncing to mobile devices requires Bluetooth and Internet connection. Syncing range: 32 feet The APP names:Veryfit for heart rate.After syncing the bracelet with app,time will sync automaticlly. Water Resistance: It is IP67,sweat, rain, splash proof.Please do not wear it when showering or swimming. We recommend charging your device every few days to ensure you are always tracking. Charge time:1-2 hours